test: repair stale skill/sandbox tests for feat/sandbox

The skill subsystem moved to Tool-Call activation and a Box-managed
skill store; several tests still asserted removed APIs and a sys.modules
stub leaked across the suite. Full unit suite now green (was 23 failing).

- test_skill_tools: drop TestSkillManagerActivation (text-marker API
  removed); rewrite TestSkillActivationHelper around the current
  skill.activation.register_activated_skill; replace the CRUD
  TestSkillAuthoringToolLoader with TestSkillToolLoader covering the
  current activate/register_skill tools and sandbox-availability gating
- test_tool_manager_native: ToolManager attr is skill_tool_loader (not
  skill_authoring_tool_loader); native loader now exposes 6 tools
  (exec/read/write/edit/glob/grep) and requires initialize() with a
  backend-available get_status()
- test_localagent_sandbox_exec: remove obsolete activation-marker
  leakage tests and their helper providers
- test_model_service / pipeline conftest: give the mocks skill_mgr=None
  so PreProcessor's local-agent skill-binding guard short-circuits
- test_n8nsvapi: stop permanently overwriting sys.modules
  ('langbot.pkg.provider.runner' etc.); save and restore around the
  import so other modules get the real LocalAgentRunner base class

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/unit_tests/provider/test_localagent_sandbox_exec.py

@@ -91,101 +91,6 @@ class RecordingStreamProvider:
         return _stream()
 
 
-class ActivationProvider:
-    def __init__(self):
-        self.requests: list[dict] = []
-
-    async def invoke_llm(self, query, model, messages, funcs, extra_args=None, remove_think=None):
-        self.requests.append(
-            {
-                'messages': list(messages),
-                'funcs': list(funcs),
-                'remove_think': remove_think,
-            }
-        )
-        if len(self.requests) == 1:
-            return provider_message.Message(
-                role='assistant',
-                content='[ACTIVATE_SKILL: demo]\nI will use the skill.',
-            )
-        return provider_message.Message(
-            role='assistant',
-            content='final answer after activation',
-        )
-
-
-class FailingActivationProvider:
-    def __init__(self):
-        self.requests: list[dict] = []
-
-    async def invoke_llm(self, query, model, messages, funcs, extra_args=None, remove_think=None):
-        self.requests.append(
-            {
-                'messages': list(messages),
-                'funcs': list(funcs),
-                'remove_think': remove_think,
-            }
-        )
-        if len(self.requests) == 1:
-            return provider_message.Message(
-                role='assistant',
-                content='[ACTIVATE_SKILL: demo]\nI will use the skill.',
-            )
-        raise RuntimeError('activation failed')
-
-
-class ActivationStreamProvider:
-    def __init__(self):
-        self.stream_requests: list[dict] = []
-
-    def invoke_llm_stream(self, query, model, messages, funcs, extra_args=None, remove_think=None):
-        self.stream_requests.append(
-            {
-                'messages': list(messages),
-                'funcs': list(funcs),
-                'remove_think': remove_think,
-            }
-        )
-
-        async def _stream():
-            if len(self.stream_requests) == 1:
-                yield provider_message.MessageChunk(
-                    role='assistant',
-                    content='[ACTIVATE_SKILL: demo]\nI will use the skill.',
-                    is_final=True,
-                )
-                return
-
-            yield provider_message.MessageChunk(
-                role='assistant',
-                content='final answer after activation',
-                is_final=True,
-            )
-
-        return _stream()
-
-
-def make_skill_manager():
-    skill_data = {
-        'uuid': 'skill-demo',
-        'name': 'demo',
-        'instructions': 'Do the demo task.',
-        'type': 'skill',
-        'package_root': '/tmp/demo-skill',
-        'sandbox_timeout_sec': 120,
-        'sandbox_network': False,
-    }
-    return SimpleNamespace(
-        SKILL_ACTIVATION_MARKER='[ACTIVATE_SKILL:',
-        detect_skill_activations=Mock(
-            side_effect=lambda content: ['demo'] if '[ACTIVATE_SKILL: demo]' in (content or '') else []
-        ),
-        build_activation_prompt_for_skills=Mock(return_value='skill prompt'),
-        get_skill_by_name=Mock(side_effect=lambda name: skill_data if name == 'demo' else None),
-        remove_activation_marker=Mock(side_effect=lambda content: (content or '').replace('[ACTIVATE_SKILL: demo]\n', '')),
-    )
-
-
 def make_query() -> pipeline_query.Query:
     adapter = AsyncMock()
     adapter.is_stream_output_supported = AsyncMock(return_value=False)
@@ -335,110 +240,3 @@ async def test_localagent_streaming_tool_error_yields_message_chunks():
 
     assert all(isinstance(message, provider_message.MessageChunk) for message in results)
     assert any(message.role == 'tool' and message.content == 'err: boom' for message in results)
-
-
-@pytest.mark.asyncio
-async def test_localagent_hides_activation_marker_before_follow_up_request():
-    provider = ActivationProvider()
-    model = SimpleNamespace(
-        provider=provider,
-        model_entity=SimpleNamespace(
-            uuid='test-model-uuid',
-            name='test-model',
-            abilities=['func_call'],
-            extra_args={},
-        ),
-    )
-
-    app = SimpleNamespace(
-        logger=Mock(),
-        model_mgr=SimpleNamespace(get_model_by_uuid=AsyncMock(return_value=model)),
-        tool_mgr=SimpleNamespace(execute_func_call=AsyncMock()),
-        rag_mgr=SimpleNamespace(),
-        box_service=SimpleNamespace(get_system_guidance=Mock(return_value='sandbox guidance')),
-        skill_mgr=make_skill_manager(),
-    )
-
-    runner = LocalAgentRunner(app, pipeline_config={})
-    query = make_query()
-    query.use_funcs = []
-
-    results = [message async for message in runner.run(query)]
-
-    assert [(message.role, message.content) for message in results] == [
-        ('assistant', 'final answer after activation')
-    ]
-    assert len(provider.requests) == 2
-    assert provider.requests[1]['messages'][-2].content == 'I will use the skill.'
-    assert '[ACTIVATE_SKILL:' not in provider.requests[1]['messages'][-2].content
-
-
-@pytest.mark.asyncio
-async def test_localagent_activation_failure_rolls_back_query_state_and_sanitizes_response():
-    provider = FailingActivationProvider()
-    model = SimpleNamespace(
-        provider=provider,
-        model_entity=SimpleNamespace(
-            uuid='test-model-uuid',
-            name='test-model',
-            abilities=['func_call'],
-            extra_args={},
-        ),
-    )
-
-    app = SimpleNamespace(
-        logger=Mock(),
-        model_mgr=SimpleNamespace(get_model_by_uuid=AsyncMock(return_value=model)),
-        tool_mgr=SimpleNamespace(execute_func_call=AsyncMock()),
-        rag_mgr=SimpleNamespace(),
-        box_service=SimpleNamespace(get_system_guidance=Mock(return_value='sandbox guidance')),
-        skill_mgr=make_skill_manager(),
-    )
-
-    runner = LocalAgentRunner(app, pipeline_config={})
-    query = make_query()
-    query.use_funcs = []
-
-    results = [message async for message in runner.run(query)]
-
-    assert [(message.role, message.content) for message in results] == [
-        ('assistant', 'I will use the skill.')
-    ]
-    assert query.use_funcs == []
-    assert query.variables == {}
-
-
-@pytest.mark.asyncio
-async def test_localagent_streaming_activation_does_not_leak_marker():
-    provider = ActivationStreamProvider()
-    model = SimpleNamespace(
-        provider=provider,
-        model_entity=SimpleNamespace(
-            uuid='test-model-uuid',
-            name='test-model',
-            abilities=['func_call'],
-            extra_args={},
-        ),
-    )
-
-    adapter = AsyncMock()
-    adapter.is_stream_output_supported = AsyncMock(return_value=True)
-
-    app = SimpleNamespace(
-        logger=Mock(),
-        model_mgr=SimpleNamespace(get_model_by_uuid=AsyncMock(return_value=model)),
-        tool_mgr=SimpleNamespace(execute_func_call=AsyncMock()),
-        rag_mgr=SimpleNamespace(),
-        box_service=SimpleNamespace(get_system_guidance=Mock(return_value='sandbox guidance')),
-        skill_mgr=make_skill_manager(),
-    )
-
-    runner = LocalAgentRunner(app, pipeline_config={})
-    query = make_query()
-    query.adapter = adapter
-    query.use_funcs = []
-
-    results = [message async for message in runner.run(query)]
-
-    assert all(isinstance(message, provider_message.MessageChunk) for message in results)
-    assert [message.content for message in results] == ['final answer after activation']